I suspect you're planting at the wrong time (too late) for your location.

Are you fertilizing at all?

It's possibly too much sun for leaves that didn't first appear during a really sunny period, combined with dry air. Some varieties may have a harder time with that, while some may not. Removing affected leaves may allow it to grow again, if it's stunted (although if it's determinate, be careful about this). It could be a copper deficiency, disease, pests or such instead, though.

Removing leaves may or may not be risky, since we don't know that this is your problem. So, giving the plants partial shade may help. Any leaves that first appear during the super sunny period should be fine if this is the issue. If brand new growth is having problems, too, it's probably something else.

Soil temperature may also be an issue, but that's a guess. Potassium levels in the soil might also be low. If the plants aren't strong, potassium levels probably are low whether or not the leaves show any signs of yellowing on the edges. It's also possible that the roots aren't healthy (which would make the plant more sensitive to sun); potassium and phosphorus should help with the roots. Over-watering, under-watering, excess nitrogen, or salty soil may also be the issue.

My guess is that the weather just changed dramatically, though.

You might check the roots for pests (like grubs, nematodes, etc.) Grubs could cause leaves to curl like this according to the link. I'm not sure how to treat grubs, but potassium would make the roots tougher and harder to eat. It should also help the plants to absorb water, and increase heat-tolerance somewhat.

I doubt those leaves will recover, though. It looks like they're trying to shade themselves. If they're getting too much light, removing them will help the plant to receive less light (and require less water, although if they're being over-watered, you'll probably want to stop over-watering).

I had a plant or two like that last year. I think they were probably potassium deficient and over-watered, which isn't a good combination (and they likely had root issues as a result).

In addition to my previous questions: do any of the other plants in your garden have that wood mulch? How long has that wood mulch been down?

What kinds of plants are you growing that have that wood mulch and are unaffected by problems?